The present invention is generally related to wireless time division duplex (TDD) or frequency division duplex (FDD) communication systems. More particularly, the present invention is related to a TDD communication system which implements an estimation method for interference signal code power (ISCP) and noise variance using a partial sample averaging.
In a UMTS terrestrial radio access TDD system, the estimation of ISCP and noise variance has become increasingly important. The receiver design requires an estimate of the noise variance for the post processing of the channel estimation and minimum mean square error-block linear equalization (MMSE-BLE) algorithm used by multi-user detection (MUD). In addition, the dynamic channel assignment dynamic channel allocation (DCA) and timeslot allocation relies on an accurate estimate of interference signal code power (ISCP) as well. As defined in the 3GPP TS25.225, the measurement xe2x80x9ctimeslot ISCPxe2x80x9d is only a measure of the intercell interference. Because intercell interference can be treated as white Gaussian noise, the estimates of ISCP and noise variance can be combined into one step. A prior estimation method uses the chip sequence in the guard period. However, due to the timing advance and the length of delay spread, there are not a sufficient number of chips in the guard period available for performing the estimation.
The present invention provides a background noise power estimator using the estimated coefficients of the channel impulse responses.